Engine prelubrication

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t_dragonas@lycos.co.uk - 17 Jul 2006 15:40 GMT

I recently had an argument with an automotive technician (i am an
automotive service advisor) about engine prelubrication. As i have
thoroughly read Jack Erjavec's excellent book "Automotive Technology, A
System's Approach" i tend to believe that you have to prelubricate a
newly rebuilt engine prior assembling it again. Technicians here have
the opinion that engine prelubrication is not something very important
for the reliability of the rebuilt engine. I would be happy to read
your thoughts on that. Thanks!

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Kevin - 17 Jul 2006 16:12 GMT

>I recently had an argument with an automotive technician (i am an
> automotive service advisor) about engine prelubrication. As i have
[quoted text clipped - 4 lines]
> for the reliability of the rebuilt engine. I would be happy to read
> your thoughts on that. Thanks!

Yeah, Jack is a great author of automotive books and I use his text in my
classes, but there are some things that are outdated. I used to think you
were supposed to lap in a new valve with valve grinding compound, like it
says in the book, but I was recently informed by some of the experts here in
this forum that this is no longer done professionally. Perhaps some of those
guys who are overhauling engines for a living could clue us in on this as
well. I am curious to know what the industry standard is on that one as
well. I have been told that using a pressurized engine pre-lube machine
prior to start up is the way to go on a rebuild and the only reason to use
assembly lube is to preserve the engine's shelf life if it will not be put
into service soon after reassembly. Seems to me using assembly pre--lube
would be the best way to go though. It's been years since I actually taught
engine overhaul and back then we would use assembly lube, then we would use
a pressure pre-lube right before cranking the engine. I did it that way
mostly to teach both methods though.
I find it hard to believe anyone would advocate not using assembly lube or
pre-lubing the engine before start up. And what would be the advantage?

Signature

Kevin Mouton
Automotive Technology Instructor
"If women don't find you handsome, they should at least find you handy"
Red Green

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Kruse - 17 Jul 2006 16:30 GMT

Seems to me using assembly pre--lube

> would be the best way to go though. It's been years since I actually taught
> engine overhaul and back then we would use assembly lube, then we would use
> a pressure pre-lube right before cranking the engine. I did it that way
> mostly to teach both methods though.
> I find it hard to believe anyone would advocate not using assembly lube or
> pre-lubing the engine before start up. And what would be the advantage?

It's been 25+ years since I went to automotive tech school, but they
were teaching back then that if you are going to be a tech just to
overhaul engines, you will soon be out of a job. I feel that the
instructors were correct, unless you are specialized or do it just on
your own vehicles. With that being said, this subject will have many
different views and probably none of them will be wrong or totally
right.
Here's my thoughts: Use assembly lube liberally. Don't use regular
grease because it is "stringy" and can plug up an oil pickup tube.
Assembly lube is not stringy. If you prelube, don't overdue it because
it can wash away your prelube and the prelube has a lot higher
stress/sheer factor than oil. Add a couple of squirts (just don't
overdue it here) of engine oil into the combustion chambers to lube the
compression ring on the initial start. Since most SM rated oils are now
low on zinc, add a couple ounces of "break-in" lube or use a diesel
rated oil on the initial oil fill. Keep the rpms higher than idle for
the first 20 minutes.
Do everything possible to get the engine to start immediately so that
very little cranking is needed. (If carbed engine, prime the carb
before cranking) 'Bout all I can think of. Arguments are welcome.

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Kevin - 17 Jul 2006 16:59 GMT

>>I recently had an argument with an automotive technician (i am an
>> automotive service advisor) about engine prelubrication. As i have
[quoted text clipped - 22 lines]
> I find it hard to believe anyone would advocate not using assembly lube or
> pre-lubing the engine before start up. And what would be the advantage?

Ok, I miss-read the original post. I thought he was talking about pre-lubing
an engine during assembly. I now realize he was talking about those pre-lube
devices that you can install on your engine to bring up the oil pressure
each time before you start it. That's a whole nuther story. I guess I don't
have any knowledgeable opinion on that one, other than I sure have had good
success with all my vehicles that did not have a pre-luber installed.

Signature

Kevin Mouton
Automotive Technology Instructor
"If women don't find you handsome, they should at least find you handy"
Red Green

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t_dragonas@lycos.co.uk - 18 Jul 2006 10:42 GMT

> >>I recently had an argument with an automotive technician (i am an
> >> automotive service advisor) about engine prelubrication. As i have
[quoted text clipped - 39 lines]
> "If women don't find you handsome, they should at least find you handy"
> Red Green

No Kevin, what i mean with "engine pre-lubing" is the operation we are
making after we have already rebuilt an engine and prior firing it up
for the first time after the rebuild. And i am not talking about those
devices that prelube the engine every time you start it.

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Scott Dorsey - 17 Jul 2006 16:16 GMT

<t_dragonas@lycos.co.uk> wrote in message

I don't know if prelube does anything at all to improve reliability these
days. But I'll say that it sure makes assembly a lot easier, and it
really reduces corrosion problems if you are taking your time doing the
work and have a lot of parts on the shelf for a while.

I could believe that prelubing isn't as important as it used to be, but
grease isn't very expensive and it makes the work a little easier, I think.
--scott

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"C'est un Nagra. C'est suisse, et tres, tres precis."

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t_dragonas@lycos.co.uk - 17 Jul 2006 16:22 GMT

> <t_dragonas@lycos.co.uk> wrote in message
> >I recently had an argument with an automotive technician (i am an
[quoted text clipped - 17 lines]
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

But why prelubing nowadays is no more important given that lubrication
systems have not been so much advanced in relation to the past?
I must note that telling prelubing i mean pressurised prelubing and not
assembly prelubing.

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Shep - 17 Jul 2006 21:49 GMT

Did pressure pre oil on ally my race engines, plus the normal assembly lube,
800 plus hp, never had a failure related to break in, that being said, it is
insurance against a failure during that critical start up period. All the
above advice applies from the other knowledgeable posters, just a matter of
how good a job you want to do. PS all race engine builders do this.

>> <t_dragonas@lycos.co.uk> wrote in message
>> >I recently had an argument with an automotive technician (i am an
[quoted text clipped - 23 lines]
> I must note that telling prelubing i mean pressurised prelubing and not
> assembly prelubing.

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smile4camera@bellsouth.net - 17 Jul 2006 23:28 GMT

> But why prelubing nowadays is no more important given that lubrication
> systems have not been so much advanced in relation to the past?
> I must note that telling prelubing i mean pressurised prelubing and not
> assembly prelubing.

Clarify for me.. are you talking about a rebuilt engine (like Jasper)
or an engine that the mechanic has just finished reassembling
themselves?

Jasper engines are already pre-run.. something that I've rebuilt
myself, even with assembly lube I'll do a little pressure prelube
before I start it the first time.

Jim

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ray - 18 Jul 2006 03:01 GMT

>>But why prelubing nowadays is no more important given that lubrication
>>systems have not been so much advanced in relation to the past?
[quoted text clipped - 10 lines]
>
> Jim

but can it ever hurt an engine to prelube it? I'm thinking "classic"
small block where you prime the engine until you get oil flowing out the
pushrods. Even on a new engine, the worst I could see this doing would
be to "wash away" the assembly lube and replace it with fresh oil, and
as long as you're not cranking for hours you should be ok, no?

I will admit I'd have no idea how to prime/prelube the LS1 in my 01 TA
seeing as how it doesn't have anything resembling a distributor, but I'm
hoping it's many more miles before it has to come out. :)

Ray

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Scott Dorsey - 18 Jul 2006 15:08 GMT

>But why prelubing nowadays is no more important given that lubrication
>systems have not been so much advanced in relation to the past?
>I must note that telling prelubing i mean pressurised prelubing and not
>assembly prelubing.

One of the reason pressurized prelubing isn't as critical is that assembly
lubes have improved so much. Hopefully you already have a pretty good film
on all the bearing surfaces before the oil system comes up to pressure.
--scott

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"C'est un Nagra. C'est suisse, et tres, tres precis."

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Donald Lewis - 17 Jul 2006 22:01 GMT

>I recently had an argument with an automotive technician (i am an
>automotive service advisor) about engine prelubrication. As i have
[quoted text clipped - 4 lines]
>for the reliability of the rebuilt engine. I would be happy to read
>your thoughts on that. Thanks!

At the very least you can fill up the oil filter before you install
it.

Don
www.donsautomotive.com

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